Elevator position reference systems and monitoring building settlement using an elevator position reference system

Abstract

An elevator position reference system and a method of monitoring building settlement using such a system. The elevator position reference system includes a hoistway extending in a vertical direction. The system also includes a first position measurement tape extending vertically along a portion of the hoistway and an upper tensioning device, connected to an upper end of the first position measurement tape so as to apply a tensioning force in the upwards vertical direction. A lower end of the first position measurement tape is fixed within the hoistway. The system also includes a second position measurement tape extend vertically along at least some of said portion of the hoistway and a lower tensioning device, connected to a lower end of the second position measurement tape so as to apply a tensioning force in the downwards vertical direction.

What is claimed is: 
     
         1 . An elevator position reference system ( 3 ), comprising:
 a hoistway ( 4 ) extending in a vertical direction;   a first position measurement tape ( 8   a ) arranged in the hoistway ( 4 ) to extend along a portion of the hoistway ( 4 ) in the vertical direction;   an upper tensioning device ( 10 ), connected to an upper end ( 20   a ) of the first position measurement tape ( 8   a ) so as to apply a tensioning force ( 30 ) to the first position measurement tape ( 8   a ) in the upwards vertical direction, wherein a lower end ( 22   a ) of the first position measurement tape ( 8   a ) is fixed within the hoistway ( 4 );   a second position measurement tape ( 8   b ) arranged in the hoistway ( 4 ) to extend along at least some of said portion of the hoistway ( 4 ) in the vertical direction; and   a lower tensioning device ( 12 ), connected to a lower end ( 22   b ) of the second position measurement tape ( 8   b ) so as to apply a tensioning force ( 32 ) to the second position measurement tape ( 8   b ) in the downwards vertical direction, wherein an upper end ( 20   b ) of the second position measurement tape ( 8   b ) is fixed within the hoistway ( 4 ).   
     
     
         2 . The elevator position reference system ( 3 ) of  claim 1 , wherein:
 the upper tensioning device ( 10 ) comprises a fixing portion ( 402 ) and a tensioning portion ( 404 ), wherein the fixing portion ( 402 ) is fixed to a first position within the hoistway ( 4 ) and the tensioning portion ( 404 ) is connected to the upper end ( 20   a ) of the first position measurement tape ( 8   a ) and is moveable relative to the fixing portion ( 402 ) so as to apply the tensioning force ( 30 ); and/or   the lower tensioning device ( 12 ) comprises a fixing portion ( 402 ) and a tensioning portion ( 404 ), wherein the fixing portion ( 402 ) is fixed to a second position within the hoistway ( 4 ) and the tensioning portion ( 404 ) is connected to the lower end ( 22   b ) of the second position measurement tape ( 8   b ) and is moveable relative to the fixing portion ( 402 ) so as to apply the tensioning force ( 32 ).   
     
     
         3 . The elevator position reference system ( 3 ) of  claim 2 , wherein the tensioning portion ( 404 ) comprises a resilient member ( 416 ). 
     
     
         4 . The elevator position reference system ( 3 ) of  claim 1 , wherein the lower tensioning device ( 12 ) comprises a weight ( 502 ) connected to the lower end ( 22   b ) of the second position measurement tape ( 8   b ) and moveable in the downwards vertical direction relative to the hoistway ( 4 ) so as to apply the tensioning force ( 32 ). 
     
     
         5 . The elevator position reference system ( 3 ) of  claim 1 , wherein the first position measurement tape ( 8   a ) and the second position measurement tape ( 8   b ) are arranged along the same wall of the hoistway ( 4 ). 
     
     
         6 . The elevator position reference system ( 3 ) of  claim 1 , wherein for the majority of the at least some of said portion of the hoistway ( 4 ), along which both the first and second position measurement tapes ( 8   a,    8   b ) extend, the first position measurement tape ( 8   a ) and the second position measurement tape ( 8   b ) are less than lm apart, optionally less than 50 cm, further optionally less than 10 cm, further optionally less than 5 cm. 
     
     
         7 . An elevator system ( 1 ) comprising the elevator position reference system ( 3 ) of  claim 1 , and further comprising:
 an elevator component ( 2 ) moving along the hoistway ( 4 ) in the vertical direction; and   at least one position measurement sensor ( 9   a,    9   b ) mounted on the elevator component ( 2 ) and arranged to output a first position measurement reading from the first position measurement tape ( 8   a ) at a first position and a second position measurement reading from the second position measurement tape ( 8   b ) at the first position.   
     
     
         8 . The elevator system ( 1 ) of  claim 7 , further comprising a computing device ( 25 ) arranged to calculate a difference between the first and second position measurement readings. 
     
     
         9 . The elevator system ( 1 ) of  claim 7 , wherein the elevator component ( 2 ) is an elevator car ( 2 ), and further comprising a computing device ( 25 ) arranged to calculate an absolute elevator car position at the first position using the first and second position measurement readings. 
     
     
         10 . A method for monitoring building settlement using an elevator position reference system ( 3 ) comprising a first position measurement tape ( 8   a ) arranged in a hoistway ( 4 ) to extend along a portion of the hoistway ( 4 ) in the vertical direction and a second position measurement tape ( 8   b ) arranged in the hoistway ( 4 ) to extend along at least some of said portion of the hoistway ( 4 ) in the vertical direction, the method comprising:
 taking a first position measurement reading from the first position measurement tape ( 8   a ) at a first position using a sensor ( 9   a ) moving with an elevator component ( 2 ) in the vertical direction;   taking a second position measurement reading from the second position measurement tape ( 8   b ) at the first position using a sensor ( 9   b ) moving with the elevator component ( 2 ) in the vertical direction; and   determining a difference between the first and second position measurement readings.   
     
     
         11 . The method of  claim 10 , wherein the first position measurement reading and the second position measurement reading are taken at the same time. 
     
     
         12 . The method of  claim 10 , wherein the elevator component is an elevator car ( 2 ), and further comprising:
 determining an absolute elevator car position at the first position using the first position measurement reading and the second position measurement reading.   
     
     
         13 . The method of  claim 10 , further comprising, during an initial learning phase, taking at least one first calibration reading from the first position measurement tape ( 8   a ) at at least one calibration position using a sensor ( 9   a ) moving with the elevator component ( 2 ) within the hoistway ( 4 );
 taking at least one second calibration reading from the second position measurement tape ( 8   b ) at at least one calibration position using a sensor ( 9   b ) moving with the elevator component ( 2 ) within the hoistway; and   storing the first and second calibration readings in a memory.   
     
     
         14 . The method of  claim 10 , further comprising transmitting at least one of: the first position measurement reading, the second position measurement reading, the difference between the first and second position measurement readings, and the absolute elevator car position, to a remote server ( 35 ). 
     
     
         15 . The method of  claim 10 , wherein the elevator position reference system further comprises:
 an upper tensioning device ( 10 ), connected to an upper end ( 20   a ) of the first position measurement tape ( 8   a ) so as to apply a tensioning force ( 30 ) to the first position measurement tape ( 8   a ) in the upwards vertical direction, wherein a lower end ( 22   a ) of the first position measurement tape is fixed within the hoistway ( 4 ); and   a lower tensioning device ( 12 ), connected to a lower end ( 22   b ) of the second position measurement tape ( 8   b ) so as to apply a tensioning force ( 32 ) to the second position measurement tape ( 8   b ) in the downwards vertical direction, wherein an upper end ( 20   b ) of the second position measurement tape ( 8   b ) is fixed within the hoistway ( 4 ).